I too have Solar, and that is one of the benefits of the SolarEdge product is it is programmable to limit or prevent battery to grid discharge and comply with the latest bureaucracy requirements, so it is supposed to be much easier to meet compliance requirements.

The points about usage patterns are always relevant. I get home well before the 4-9pm peak. Since I work M-F, I would have the full battery capacity available on weekends. In my area, TOU and 4-9pm peak are now 24/7/365 so I hope not to change our lifestyles from 4-9pm.

I used to get over $.40 credit per excess kWh produced and purchase at ~$.25 in the evening. But now I am credited ~$.25 for excess and purchase at ~$.45 from 4-9pm.

I sure wouldn't want to add the extra daily cycling to my car's battery. If a dedicated battery degrades, I just keep using it until I decide it's cost effective to replace it. If my car's battery degrades too much, my car becomes useless. Also, you've created a false equivalency on your pricing scenario. If you're just using the tail end of your car's capacity after your driving day to cover a small peak period, you probably only need a small (10kWh ?) battery to give you that same utility. Besides, how complex is the infrastructure if you buy the solution off the shelf?

"Degrades too much" is dependent on your personal circumstances. The equivalency is not false on the weekends, where my car is usually in the garage all day and the entire family is home and we are more likely to be doing laundry, etc. As far as the weekday shaving I do only need a small amount of capacity, which is why I'm not worried about additional cycling or battery degradation for my car. An off the shelf solution has limited complexity but my point is it will cost an extra $6k for an additional battery. The complexity and infrastructure comments apply to less expensive additional battery options like re-purposed EV batteries or other not-off-the-shelf solutions.

I'm sure that the solutions that fit my situation and comfort zone are not well suited for all. You are free to make your own choices and spend your money buying all the batteries you need. By the time my battery degrades to 75% or less I expect we will be 10 years into the future and have many more cost effective options, both for home storage and refurbishing the battery pack on my Rav4. For me it's as much about the independence and developing alternate solutions as it is about the dollars and cents.

I'm sure at some point the bureaucracy will drive me to virtually go off-grid completely within the limits of the law (I think that's where I was before they changed the net-metering times and rates). At that time if my car only has 50% capacity, it's still a 20kW battery that I already own and I can use it to run errands if I choose. Or just park it and take it off insurance, etc. Or re-sell it and buy Powerwall batteries. It keeps open so many more options than buying dedicated batteries now. In my world, it's the future and will be influenced primarily by the cost of insurance for my "mobile battery pack." At this time, in many cases, it's cheaper to buy an electric car than it is to buy dedicated batteries. Maybe I'll buy a new Leaf to power my home.